[[a1, a2], [b1, b2], [c1, c2]]
[[[a1, a2], [b1, b2]], [c1, c2]]
[[a1, a2], [[b1, b2], [c1, c2]]]
{b1=b2, a1=a2, c1=c2}
[{b1=b2, a1=a2}, c1:c2]
[a1:a2, {b1=b2, c1=c2}]
[1, 2, 3, 4, 5, 9]
[1, [2,3,4,5], 9]
[1, [2,3,4,5], 9]
[1, 2, 3, 4, 5]
[1, [2,3,4,5]]
[1, [2,3,4,5]]
[2, 3, 4, 5, 9]
[[2,3,4,5], 9]
[[2,3,4,5], 9]
